Vol. 19 No. 1 (1986)

. This paper describes the development of pitch control strategy for space craft possessing a Direct Broadcasting Satellite configuration which is assumed to consist of a main rigid body plus large flexible solar arrays. The bias momentum concept of the double gimballed reaction wheel is applied for generating the pitch control torques. It is found that the wheel acceleration/deceleration produces an undesired cross coupling in roll, yaw, and pitch axis, In order to minimize this coupling, the pitch control strategy is then constructed based on the Pontryagin

. PWM modulator with feedback analog is often used in a voltage/current control system, but sometimes problems arise in which the modulator could not be used with this method. To overcome this problem a programmed numeric PWM modulator is used. This paper discusses the working procedure and realization from the software and hardware point of yiew by using 8085 microprocessor. One of its application is to control the firing time of power switching transistor in a DC converter (BUCK) where the input BUCK is connected to the solar cell panel and the output side is connected to the battery. With…